/* eslint-disable */
import { Vector2 } from 'three'

/**
 * @author Felix Turner / www.airtight.cc / @felixturner
 *
 * Bad TV Shader
 * Simulates a bad TV via horizontal distortion and vertical roll
 * Uses Ashima WebGl Noise: https://github.com/ashima/webgl-noise
 *
 * Uniforms:
 * time: steadily increasing float passed in
 * distortion: amount of thick distortion
 * distortion2: amount of fine grain distortion
 * speed: distortion vertical travel speed
 * rollSpeed: vertical roll speed
 *
 * The MIT License
 *
 * Copyright (c) Felix Turner
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 *
 */

const uniforms = {
  time: {type: "f", value: 0.0},
  distortion: {type: "f", value: 9.0},
  distortion2: {type: "f", value: 6.0},
  speed: {type: "f", value: 0.2},
  rollSpeed: {type: "f", value: 0.1},
  textureFactor: {type: "v2", value: new Vector2(1, 1)}
}

const vertexShader = `
  varying vec2 vUv;
  uniform vec2 textureFactor;
  void main() {
    vUv = vec2(0.5 + (uv.x - 0.5) / textureFactor.x, 0.5 + (uv.y - 0.5) / textureFactor.y);
    vec4 mvPosition = modelViewMatrix * vec4(position, 1.0);
    gl_Position = projectionMatrix * mvPosition;
  }
`

const fragmentShader = `
  uniform sampler2D texture;
  uniform float time;
  uniform float distortion;
  uniform float distortion2;
  uniform float speed;
  uniform float rollSpeed;
  varying vec2 vUv;

  // Start Ashima 2D Simplex Noise
  vec3 mod289(vec3 x) {
    return x - floor(x * (1.0 / 289.0)) * 289.0;
  }

  vec2 mod289(vec2 x) {
    return x - floor(x * (1.0 / 289.0)) * 289.0;
  }

  vec3 permute(vec3 x) {
    return mod289(((x*34.0)+1.0)*x);
  }

  float snoise(vec2 v) {
    const vec4 C = vec4(0.211324865405187,  // (3.0-sqrt(3.0))/6.0
      0.366025403784439,  // 0.5*(sqrt(3.0)-1.0)
      -0.577350269189626,  // -1.0 + 2.0 * C.x
      0.024390243902439); // 1.0 / 41.0
    vec2 i  = floor(v + dot(v, C.yy) );
    vec2 x0 = v - i + dot(i, C.xx);

    vec2 i1;
    i1 = (x0.x > x0.y) ? vec2(1.0, 0.0) : vec2(0.0, 1.0);
    vec4 x12 = x0.xyxy + C.xxzz;
    x12.xy -= i1;

    i = mod289(i); // Avoid truncation effects in permutation
    vec3 p = permute(permute( i.y + vec3(0.0, i1.y, 1.0 ))
    + i.x + vec3(0.0, i1.x, 1.0));

    vec3 m = max(0.5 - vec3(dot(x0,x0), dot(x12.xy,x12.xy), dot(x12.zw,x12.zw)), 0.0);
    m = m*m;
    m = m*m;

    vec3 x = 2.0 * fract(p * C.www) - 1.0;
    vec3 h = abs(x) - 0.5;
    vec3 ox = floor(x + 0.5);
    vec3 a0 = x - ox;

    m *= 1.79284291400159 - 0.85373472095314 * (a0 * a0 + h * h);

    vec3 g;
    g.x = a0.x * x0.x + h.x * x0.y;
    g.yz = a0.yz * x12.xz + h.yz * x12.yw;
    return 130.0 * dot(m, g);
  }
  // End Ashima 2D Simplex Noise

  void main() {
    vec2 p = vUv;
    float ty = time * speed;
    float yt = p.y - ty;
    //smooth distortion
    float offset = snoise(vec2(yt * 3.0, 0.0)) * 0.2;
    // boost distortion
    offset = offset * distortion * offset * distortion * offset;
    //add fine grain distortion
    offset += snoise(vec2(yt * 50.0,0.0)) * distortion2 * 0.001;
    //combine distortion on X with roll on Y
    gl_FragColor = texture2D(texture, vec2(fract(p.x + offset), fract(p.y - time * rollSpeed)));
  }
`

export { vertexShader, fragmentShader, uniforms }
